In submersible electrical devices such as motors or pumps, it is sometimes necessary to bring the leads from the winding of the motor from a sealed oil filled cavity containing the motor to an adjacent isolated cavity wherein connections are made to an outlet cord and possibly a pressure switch.
Past efforts to meet the sealing requirements have largely centered around three basic approaches all workable but possessing disadvantages one of which being excessive costs. These current methods include (1) the use of the well known threaded compression screw to effect a seal to the outer diameter of the lead which is emerging from a threaded hole in the cavity, (2) the screwing down of a metal plate to compress a follower washer against a rubber ring seal which in turn compresses against the outer diameter of the lead and (3) the potting of an epoxy resin around the lead and bonding to the internal diameter of the hole in the cavity.
The costs involved in using threaded components is obvious and is amplified by the assembly of multiple parts. Another disadvantage is the excess of radially inward force due to the high mechanical advantage of the threads which sometimes create a thinning down of the lead insulation to the point where it becomes susceptible to mechanical abuse. Potting processes are at best inconvenient and often messy creating bottlenecks in high production assembly due to the need for application of heat and/or long cure times.
The present invention is intended to eliminate the aforementioned disadvantages by using unique and simple means for effecting a suitable seal where it is required to bring the motor leads from an oil filled cavity into an adjacent cavity for making electrical connections.